1 tablespoon vegetable oil
4 boneless, skinless chicken thighs
½ onion, coarsely chopped
4 cloves garlic
1 (4-ounce) can diced green chiles
¼ cup chopped fresh cilantro
1 to 2 jalapeños, seeded and coarsely chopped
2 teaspoons ground cumin
1 cup shredded Monterey Jack cheese
½ cup sour cream
HEAT a large skillet over medium heat; add the oil. Once the oil is hot, add the chicken and cook for 10 minutes; turn and cook for an additional 5 minutes.
Meanwhile, in a blender or food processor, combine the onion, garlic, 1 cup water, chiles, cilantro, jalapeños, and cumin. Blend until smooth.
Pour the sauce over the chicken. Cover and cook until the chicken is tender and the internal temperature reaches 165°F, about 10 minutes.
Transfer the chicken to a serving dish. Add the cheese and sour cream to the pan and cook over low heat, stirring constantly, until the cheese is melted and the sauce is thickened, 1 to 2 minutes.